Principles of database and knowledge-base systems, Vol. I
Principles of database and knowledge-base systems, Vol. I
A characterization of globally consistent databases and their correct access paths
ACM Transactions on Database Systems (TODS)
Computational problems related to the design of normal form relational schemas
ACM Transactions on Database Systems (TODS)
Efficient optimization of a class of relational expressions
ACM Transactions on Database Systems (TODS)
Testing implications of data dependencies
ACM Transactions on Database Systems (TODS)
Equivalences Among Relational Expressions with the Union and Difference Operators
Journal of the ACM (JACM)
On the Complexity of Testing Implications of Functional and Join Dependencies
Journal of the ACM (JACM)
Testing satisfaction of functional dependencies
Journal of the ACM (JACM)
Efficient query answering in the representative instance approach
PODS '85 Proceedings of the fourth ACM SIGACT-SIGMOD symposium on Principles of database systems
A relational model of data for large shared data banks
Communications of the ACM
Can we use the universal instance assumption without using nulls?
SIGMOD '81 Proceedings of the 1981 ACM SIGMOD international conference on Management of data
Optimal implementation of conjunctive queries in relational data bases
STOC '77 Proceedings of the ninth annual ACM symposium on Theory of computing
Polynomial time designs toward both BCNF and efficient data manipulation
SIGMOD '90 Proceedings of the 1990 ACM SIGMOD international conference on Management of data
Independence-reducible database schemes
Journal of the ACM (JACM)
Independent Database Schemes under Functional and Inclusion Dependencies
VLDB '87 Proceedings of the 13th International Conference on Very Large Data Bases
Why is the snowflake schema a good data warehouse design?
Information Systems
Proceedings of the twenty-second ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
| Hi-index | 0.01 |
A simple characterization of independent database schemes is proved. An algorithm is given for translating a tableau T, posed as a query on a representative instance, to a union of tableaux that is equivalent to T, but can be applied directly to database relations. The algorithm may take exponential time (in the size of T and the database scheme), and it is applicable only to independent database schemes. If T is a just a projection of a representative instance, then the algorithm has a simpler form (which is still exponential in the worst case) and is polynomial in some cases.